Orthogonal Frequency-Division Multiplexing (OFDM) is a method of encoding digital data on multiple carrier frequencies and it is a frequency-division multiplexing (FDM) scheme used as a digital multi-carrier modulation method. According to the OFDM, a large number of closely spaced orthogonal subcarrier signals are used to carry datan several parallel data streams or channels. Typically, design parameters for an OFDM system are derived according to system requirements. Parameters to be considered include, for example, subcarrier spacing, guard time/cyclic prefix and symbol duration, transmission time interval (TTI), etc.
Recently, diverse requirements are constantly demanding, and for different deployment scenarios and different carrier frequencies, it may require different numerologies. Thus, different numerologies are required in new radio (NR).
In a technical document “Mixed numerology in an OFDM system”, Ericsson, 3GPP RAN1#85, 2016, May, there is proposed a mixed numerology in an OFDM system wherein it is proposed to introduce guard band between multiplexed numerologies to reduce inter-numerology interference. However, in this document, it only focus on the inter-numerology interference and does not give any idea about how to multiplex numerologies.
Thus, in existing solutions, there is no a solution about how to support different numerologies in the same band yet and therefore there is a need to enable numerology multiplexing to support multiplexing of different services with diverse requirements in the same frequency band.